I would experiment. Keep a control sample that you do not treat and a handy notebook to keep a record of what you did.
I don't add microbe supplements, but then I am starting over at my place after an infestation of invasives--most of which are nitrogen fixers. I plan some hugel strips to go in this winter made from the bodies of the trees I am cutting now. After that will go a series of ground buster cover crops. I think once you get the components in there, the microbes will pretty much come by themselves. I think it might depend on how much rooting activity you can get, such as might occur in a fast succession of cover crops, cruciferous vegetables, and daikon radish, in each case leaving the roots in place to decay into the soil.
In the fermentation of vegetables, Sandor Katz has said that there is a natural progression of the types of microbes that are in the fermented vegetables. So even if you innoculate initially with xy microbes you will wind up with wz microbes. I think that probably happens in soil also, that there is a natural progression within the rhizome. Now how do you measure that? Ill have to think about it for a while. Possibly there are index plants you could use to check how your microbes are doing.
